Brush for electrical machinery.



0. E. BECKER.

BRUSH FOR ELECTRICAL MACHINERY.

APPUCATION nuzn MAR-11.1918.

Patented Oct. 22, 19B.

Ste 111 which ,Ifmake, reference.

encountered in tendency to spread or my.

omvmn. mom, or oax rank, ILLINOIS.

v mie m ELECTRICAL MACHINERY.

To all whom it mayconcem."

Be it known that I, 0mm E; Bncmm, a citizen" of "the United "States,residing at Oak Park, in the county of Cook and State of Illinois, haveinvented a" certain new and usefulfI rovement in Brushes for ElectricalvMac inery, of which the" following is a full, clear, concise, and exactdescription, reference being ha'dto the accompanying drawings, formingapart ofthis' specification-: a

My invention relates to brushes for electricalmachinery.

The matter of maintaining electrical-contact between 'a stationaryterminal and a moving, commutator or collecting rin'gfor the like, isone of thernostdiflicultpractical problems in the industry Numerousforms of brushes havebeendevisedl Some have found particularfavoriorsp'ecial uses. Ihe gauze brush has persisted from the earl est es of,the development of the electrical ustry and islnew perhaps the best"fitted land i the; most widely used forglow voltage purposes. v outlineoftheadvantages ofthe gauze brush and its. relation tothe other types ofbrushes is set ou iniBa nfi'N 2 84ei wave ebserved th'at"Qnenftiiedifliculties uz'efbrushes is the Gauze Brushes are generally made by"windin a strip of wire gauze into a roll, on

a ,man 1' l, :then' *rem'ovin gthe mandrel? and rolling or prejssi'ngthe roll" of gauze' into rectangular prismatic form; f The roll ng orpressing compresses the gauze and makes the texture close andcompact;'atthe'samemne it preserves the springiness of the material topermit it to adapt itself-to seatingon the com nutator or" ringsurface;- The top of the brush is generally dipped into solder and"thereby filled to preserve the form of thehrush as wellias m prevideasolid part for attachment" of the-lead or leads; p

The" qobj'ect of my mate isto provide meansfor preventing thespreadingrtorfraying" without ues'aoym or ser iousl iinp airing theresiliency and springmess orf'ventiv ed mit'the invention in a m ber' ofdiiierent ways;,some ofwhlch I shall set forthat len' I 111. Tn generalthese differ- "entmethods' iii aim t'o secure a connection Specificationof Letters Patent.

Patented Oct. 22,1918.

Application filed March 11, 1918. 'SerialNo. 221,665.

of limited extent between the gauze of different layer-sin the-brush.This cennection may be made by causing adhesion between surfacecoatingsaon adjacent layers, by local- 1Z6Cl' fillings of acemen-titious material such assolderfby localized weld s, by lacingWires, or by other means.- 4

In order to acquaint more fully those skilled in the art with thewnatureof 'theinvention, I shall now set outflin detail one manner ofpractising the invention.

In the accompanying drawings which form a part of the presentspecification,

Figure '1 is a cross-sectional view of a brush constructed in accordancewith my invention, whereby the limited connection between layers issecured by spot welding;

"FigJQ is a similar View o-f'abrushjconstructed in accordance with'myinvention by spot soldering;

Fig. 3 is an isometric view of a brush made of gauze, having a surfacecoating which is caused toadhere at localized points to securcconnection between the different layers of auze;

i'g. 4 is an isometric view of a sheet of gauze having localizedcoatings or fillings of lubricating metal such as tin orthe like;

FigL-Sis an isometricview ofa. brush formed ofthe gauze in Fig. 4,showing the as the broad idea of'forming a brush from gauze isnot myinvention, I do not consider that it is necessary to describe in detailthe steps of first rolling the gauze ona mandrel,

.then withdrawing the mandrel and there after forming the rolls ofgauzeinto a prismatic block or brush. The particular manner of formingthe sheet gauze into theprismatic brush 1s set forth in the patent toGutinann, No. 599,781.

In Fig. 1 I have illustrated a brush made up of gauze in which a few ofthe outer layers are joined together by local spot "welds as shown at10. This spot welding is preferably done in an electricalWeldingmainterconnection, so that there is farless tend- I ency for thesides of the brush to bulge out and bind in the holderyas has previouslybeen the case. At the same time, the springiness or resiliency and theventilating ability of the brush as a whole is not materially impairedand the brush is able to adapt itself to the surface of the commutator.

In Fig. 2 I have illustrated a brush made up of a plurality of sections11, whichare inclosed by a common wrapping of a sheet or strip of gauze,binding the sections together. V In this case the wrapper 12 and thesections 11 are joined together by local fil1 ings of tin solder or thelike 13, which may be applied in any preferred manner to join thewrapping-.12 with the material of the sections II. It is to beunderstood that welding as disclosed in connection with Fig. 1, may beemployed to fasten the sections and the wrapper together, or that thebrush of Fig. 1 mlght be made up of sections but connected by spotwelds.

In Fig. 3 I have illustrated a brush formed of gauze having alubricating coating as set out in Patent No. 1,228,484. The lubricatingcoating may be applied either before or after forming the gauze into thebrush as is I set out in that patent. When the brush has been formedwith the lubricating coating I provide a series of localized connectionsby applying ressure and heat at the various polnts to orm a unionbetween the lubricating'coating of diflferent layers, as shown at 14 inFig. 3; This may be secured by applying heat electrically, by applying ahot iron, or an open flame, or in any preferred manner. The essentialidea is to secure a limited connection between layers, so that thetendency to spread or fray will be very largely counteracted withoutimpairing the resiliency and springiness of the brush.

In Figs. 4 and 5 I have illustrated the manner of making up a brush ofthis character by providing localized fillings of tin,

lubricating metal or the like, at 15, in the gauze sheet 16, prior toforming the same into the block or brush 17. In this event the gauze,after it'is rolled into the block or brush form, is subjected topressure and heat to cause the fillings 15 to adhere to adjacent layers.of gauze so as to secure union between layers. While I term thelocalized applications of tin as shown at 15 in Figs. 4 and 5 asfillings, it is to be understood that the meshes of the gauze need notactually be filled, but that any quantity of tin or other unitin metalin quantity sufiicient to form a union etween adjacent layers isconsidered to come within the term filling.

- In'Fig. 6 I have illustrated the manner in which the outer layers ofthe gauze of the .solder ad eres.

, brush.

otherri 'dly'in A V A .0? heclas chm-r brush maybe united by solder orthe like by first applying a flux to the outer layers and then unitingthese la ers by solder.

. In carryingiout this particular embodiment of the process I provide ahot metallic plate as shown at'16, which has a thin film of melted tinor solder 17 thereupon. After the flux is applied to the outer: layersof gauze on the brush, the brush is pressed against the plate 16 wherebythe thin film 0 tin or solder 17 permeates the outer layers of the brushto. a limited. extent, causing union between these layers as indicatedat 18 in Fig. 6. i

I have found that with the above method the oint at which the tin orsolder is made to adhere, may be controlled by the a plica tion ofthefiux. Thus, as shown in ig. 7, I may apply the flux only in strips asshown to secure localized fillings 19 in the form'of longitudinal stripsin the outer layers of the brush. It is apparent that local spotfillings may be secured in the same manner by localizing the ap licationof the flux and thus controllin ,t e point Iat"which the tin or Whetherthe local adhesions be caused by welding or. soldering the efl'ect is'the same, namely a fixed molecular union between the adjacent parts. j

I do not intend to be limited to the details shown and described, butintend toconvey theessential and novel idea of forming limited unionbetween different layers'of the gauze brush in order to hold the sidesagainst bowing out and against 'fraying, without materially destroyingor impairing the. resiliency or yentilation of the brush. This idea is''notrtobe confused with fillingtheend of the'b'll'lh'with solder as thathas no beariu on my invention it is never intended t at'thej end of thebrush which is filled with solder is to form actual contact with thecommutator. A gauze brush which would be completel filled with solderwould not be difierent. m 'a; solid metal brush and would be subjectto'all'the difliculties attendant upon the use of the solid metal brush.a y y y l I claim:

means engaging only-a limited number 0 the outer layers of the gauzeforholding the outer layers of 'gauze a inst spreading.

2. A gauze brush of o longcross section, having means providinglocalized areas of adhesion betweenadjac'ent layers of a part of the.brush only at the wider sides of the an brush of the class described,comprising layers of gauz thelouter layers only of WhlCh are causetoadhere'to each areas,

. j i I 1'. gauze brushformed of layers of" metallic gauze, havinglocalized prising layers of gauze, having cementing means for holdingthe outer layers of gauze against spreading or frayin said means beingformed of material substantially the same or of a lower degree ofhardness than the gauze of the brush.

' 5. The method of causing adhesion between the outer layers of a gauzebrush, which consists in applyin a cleansing compound to the areas whicit is desired to cause to adhere, then heating the areas to the point offusing the adjacent metallic surfaces.

6. The method of treating gauze brushes to prevent bowing or spreadingwhich consists in applying a fusible metal to the surfaces of the gauzeto be united and locally applying heat to cause a union between parts ofthe gauze adjacent to the surface of the brush.

7. The method of treating gauze brushes to prevent bowing of the outerlayers, which consists in applying a cementitious material for forminglocal adhesions onl between the outer parts of the gauze of t e brush.

8. The methods of treating gauze brushes to prevent bowing of the outerlayers,

which consists in forming local adhesions only between parts of thegauze of the brush, said local adhesions including parts of the outerlayers of the brush.

9. The method of treating gauze brushes to prevent bowing or spreadingof the outer layers, which consists in providing fillings of tin or thelike for parts of the brush only, whereby the natural resiliency andventilation of the brush is not materially impaired.

10. The method of treating gauze brushes to prevent bowing or spreadingof the outer layers, which consists in locally cementing the outerlayers of gauze at a plurality of points to the layers beneath.

11. A gauze brush having front and back faces and means along the entirefront and back faces for causing localized adhesions between the outerlayers of the gauze to prevent spreading or fraying of the gauze.

12. A gauze brush having local areas only ofladhesion between a part ofthe layers on n witness whereof I hereunto subscribe my name this th dayof March, A. D., 1918.

OLIVER E. BECKER.

Copies of this patent may be obtained for five cents each, by addressingthe Commiuioner o! Patentn, Washington, I). G."

